Earthquake · reviewed by a seismologist
M 2.0md
Earthquake near Byron, CA
No earthquake was likely felt in Byron in the 24 hours to 9:11 pm PST (05:11 UTC). The last one was M 3.5, 53 km (33 mi) SSE, at 7:21 am PDT on 27 September 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near Byron
This page: a magnitude 2.0 earthquake was recorded 12 km (8 mi) southwest of Byron, CA, at 10:12 am PDT on 2 April 2020 (17:12 UTC), 13 km deep. 2 people have reported feeling it to USGS.
USGS: 12km SW of Byron, CA
13 km (8 mi) N of Livermore, CA · 57 km (35 mi) N of San Jose, CA
- When
- 10:12 am PDT on 2 April 2020 ()
- Where
- 12 km (8 mi) southwest of Byron, CA · earthquakes near Byron
- Magnitude
- M 2.0 (md)
- Depth
- 13 km below the surface
- Felt
- 2 reports · strongest reported intensity I
- Nearest
- Contra Costa County, 22 km NW
- Nearest mapped fault
- Greenville fault, 6 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2414 days ago
Earthquake alerts for Byron, CA
Get a notification in this browser when USGS records an earthquake near Byron, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Byron, 12 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Earthquakes near other towns within 30 km: Livermore, Blackhawk, Brentwood, Discovery Bay, Diablo, Mountain House.
How big was it?
This earthquake released about 33 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 450,000× the energy of this one
- Magna, Utah 2020 M 5.7 320,000× the energy of this one
- Around the size people start to feel M 3.0 29× the energy of this one
- This earthquake M 2.0 about 33 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
The largest earthquake within 50 km since 2016 was M 4.5 on 2019-10-15 — about 4,400 times the energy of this one.
Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:
- 5.8 The 1980 Livermore, California Earthquake · 4 km NNW of this epicentre
- 5.7 15 km NE of East Foothills, California · 37 km S of this epicentre
- 5.5 6 km NNE of East Foothills, California · 41 km S of this epicentre
- 5.4 9 km NE of Livermore, California · 7 km SE of this epicentre
- 5.3 6 km E of East Foothills, California · 46 km S of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 37.8035, -121.7545. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 22 km (13 mi) | NW | earthquakes near Contra Costa County |
| Alameda County, CA | 22 km (14 mi) | SW | earthquakes near Alameda County |
| San Joaquin County, CA | 45 km (28 mi) | ENE | earthquakes near San Joaquin County |
| Solano County, CA | 54 km (34 mi) | NNW | earthquakes near Solano County |
| Santa Clara County, CA | 65 km (40 mi) | S | earthquakes near Santa Clara County |
| San Mateo County, CA | 69 km (43 mi) | SW | earthquakes near San Mateo County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
51 earthquakes have been recorded within 50 km since this one.
- 1.5 1km SSE of Pleasanton, CA
- 1.6 14km SE of Livermore, CA
- 1.9 2km NNE of Alameda, CA
- 1.9 1km NW of Pleasant Hill, CA
- 1.8 10km NE of Blackhawk, CA
- 3.4 8km NE of Alum Rock, CA
- 1.8 4km E of Livermore, CA
- 2.1 8km ENE of Alum Rock, CA
- 1.6 1km SSE of San Ramon, CA
- 2.0 2km E of Berkeley, CA
- 2.6 2km E of Berkeley, CA
- 2.2 5km SSE of Newark, CA
- 1.9 1km WSW of Pittsburg, CA
- 1.7 1km S of Kensington, CA
- 2.0 1km W of Pleasant Hill, CA
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.